Mammalian and insect cells are grown for biological testing and other uses. A starter culture is placed in a growth media such as Grace's media, which is contained in a generally flat bag ranging from 2 liters to 100 liters in volume. These bags have standard fittings on them, typically made by Colder Products Company, and covered by U.S. Pat. No. 5,052,725. The standard fitting is small, about ¼ inches (about 6 mm) in diameter. The bags are filled by pouring the Grace's media or other equivalents into the ¼ inch diameter fitting from the open lip of the bottle in which the Grace's media is shipped or addition of culture , which results in spillage of media that costs $300 to $1,000 per liter. Alternatively, the bags are filled by hand using pipettes, which takes a long time, exposes the media and culture to contamination, and still results in spillage. Pumps can also be used to transfer the growth media to the bags, but the pumps use ¼ inch tubing and fill the bag slowly and can contaminate the bags if not cleaned adequately. There is thus a need for an improved way to quickly transfer the growth media through the fitting into the bags while reducing spillage. There is a need for a direct and easy transfer of growing cells into these bags.
The bags are placed on a rocker which rocks from side to side. The bags have a smooth bottom and are rocked gently because the insect and mammalian cells rupture easily. A starting culture having a concentration of about 4×e5 is grown to 1-2×e6. Higher concentrations are desirable, and shorter times are also desirable as it decreases processing time. There is thus a need for a way to culture these cells to higher densities, and to do so in a shorter time.
These cells are often infected with a virus through smaller, ⅛ inch diameter ports (about 3 mm dia.) provided with the bag. Cell growth is continued for 48-72 hours after infection, at which time the cells are harvested. But the cells typically require a viability of about 90% or more to make harvesting viable. There is thus a need for a way to more consistently grow cells with not only desired viability, but higher viability.